JPH0749005A - Exhaust heat recovery power generation control device - Google Patents

Abstract

PURPOSE:To facilitate stable and high-efficiency control in relation to transient load fluctuation by adding the inlet and outlet medium temperature change rates of the high and low pressure evaporators of an exhaust heat system and the change rates on the cooling water temperature of a condenser and the inlet medium temperature of the high and low pressure evaporators respectively as bias signals to control the opening of an exhaust heat flow regulating valve. CONSTITUTION:The inlet and outlet medium temperature change rates of a high pressure evaporator 5 and a low pressure evaporator 7 in an exhaust heat system 1, and the change rates on the cooling water temperature of a condenser 13 and the inlet medium temperature of the high pressure evaporator 5 and low pressure evaporator 7 are respectively added as bias signals to control the opening of an exhaust heat flow regulating valve 33. Control is thereby performed following the set power of the generator 12 of a medium turbine 11, and the respective heat exchange rates of the exhaust heat system 1, a medium system 2 and the condenser 13 of a cooling water system 3 are improved in such a way as to reduce the inlet pressure fluctuation of the medium turbine 11. Accordingly, even with the generation of fluctuation to the temperature and exhaust heat flow of the exhaust heat system 1 in relation to the setting of power load of a turbine generator, high efficiency operation can be performed with stable control on transient load fluctuation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust heat utilization power generation control device utilizing exhaust heat obtained from hot water of an industrial plant or underground.

[0002]

2. Description of the Related Art Thermal power generation, hydroelectric power generation,
In addition to the nuclear power generation method, there are various special power generation methods. As one of the special power generation methods, there is a power generation method that uses exhaust heat obtained from an industrial plant or underground.

In this type of power generation system, the turbine is rotated by steam similarly to the thermal power generation, but the fuel cost required for rotating the turbine can be greatly saved as compared with the thermal power generation. In recent years, it has begun to receive attention from the viewpoint of resource utilization.

Generally, in an exhaust heat utilization power plant, high temperature hot water and exhaust heat are supplied to an evaporator and a preheater by an exhaust heat pump and exchange heat with a medium. Then, the evaporative gas whose temperature has risen due to heat exchange in the evaporator is supplied to the medium turbine,
It drives a medium turbine generator to generate electricity. The exhaust gas of the medium turbine flows into a condenser, is cooled by cooling water, and is collected in a hot well tank and circulated. In the condenser, the exhaust gas of the medium turbine is cooled with cooling water.

By the way, in the conventional exhaust heat utilization power generation control device, no particular control is performed on the flow rate of hot water, and all the exhaust heat obtained from the industrial plant is used to drive the turbine. It is designed to operate at maximum power.

[0006]

However, in the above-described power generation control by the maximum electric power operation, when the exhaust heat flow rate or the exhaust heat temperature from the industrial plant or the like changes, the generator output also immediately fluctuates, and it is left up. There is a drawback that is the control of.

First, when the exhaust heat flow rate and exhaust heat temperature of the primary system fluctuate during current load control, the output of the turbine generator is greatly influenced by the heat exchange performance of the preheater and the performance of the evaporator. It In other words, the level of the evaporation amount of the medium in the evaporator fluctuates due to the transient exhaust heat flow rate and temperature fluctuations,
Along with this, the evaporative gas pressure of the medium also fluctuates significantly. Therefore, the inlet flow rate and pressure of the medium turbine fluctuate, and the output of the medium turbine generator fluctuates significantly.

Secondly, as the load of the medium turbine generator fluctuates, the exhaust gas spent for driving the medium turbine changes in transient flow rate and temperature, and the cooling temperature of the medium also fluctuates due to the secondary delay of the condenser. To do. In this way, with the transient fluctuations in exhaust heat temperature and exhaust gas flow rate, the flow rate of the medium flow rate to the heat exchanger fluctuates, which causes a secondary delay when heat is exchanged in the preheater and the evaporator. Output fluctuates,
There is a problem that the control system is not stable.

Therefore, the present invention has been made in consideration of the above circumstances, and the turbine power generation is performed even if the exhaust heat temperature variation and the exhaust heat flow rate variation of the exhaust heat system occur with respect to the power load setting of the turbine generator. It is an object of the present invention to provide an exhaust heat utilization power generation control device that prevents fluctuations in the output of a machine.

[0010]

High-temperature hot water and exhaust heat are taken in by an exhaust heat pump and sequentially supplied to a high-pressure evaporator, a high-pressure preheater, a low-pressure evaporator and a low-pressure preheater, and heat exchange with each of them is performed. The system, the medium from the hot well tank to the low-pressure preheater, the low-pressure evaporator, the high-pressure preheater, and the high-pressure evaporator is sequentially flowed by the medium, heat is exchanged with the high-temperature hot water and exhaust heat to raise the temperature. The low pressure evaporator and the high pressure evaporator to vaporize the medium to a specified pressure,
The evaporative gas of the medium is supplied to the high pressure side and the low pressure side of the medium turbine to drive the generator of the medium turbine, the exhaust gas of the medium turbine flows to the condenser, is cooled by cooling water, and is collected in the hot well tank and circulated. In the exhaust heat utilization power generation control device for controlling the exhaust heat utilization power generation plant, which comprises a cooling water system for cooling the exhaust gas of the medium turbine with cooling water in the condenser, a flow rate detector is provided in the exhaust heat system. And a first temperature detector, a second temperature detector, a third temperature detector, a fourth temperature detector, and a flow rate control valve, respectively,
On the low pressure side of the medium system, a first pressure detector and a first level detector are arranged on the low pressure evaporator, a level control valve is arranged on the inlet side of the low pressure evaporator, and on the high pressure side of the medium system. Is
A second pressure detector and a second level detector are arranged in the high pressure evaporator, a level control valve is arranged on the outlet side of the low pressure preheater, and a third pressure is arranged on the inlet side of the medium turbine on the high pressure side of the medium system. A detector is disposed, a fourth pressure detector is disposed on the inlet side of the medium turbine on the low pressure side of the medium system, and a pressure control valve is disposed on the bypass system, and a pressure control valve is disposed on the bypass system. A fifth temperature detector is disposed on the outlet side of the condenser of the medium system, a sixth temperature detector is disposed on the hot well tank, and a temperature control valve and cooling water are disposed on the cooling water system. A pump and an electric power setting means for outputting an electric power setting signal of the medium turbine, for calculating and outputting an exhaust heat flow rate deviation signal between the electric power setting signal and the exhaust heat flow rate signal of the flow rate detector, The pressure signal of the first pressure detector and the fourth pressure First bias signal setting means for outputting a first bias signal based on the deviation signal from the pressure signal of the output device, addition / subtraction for adding / subtracting the exhaust heat flow rate deviation signal and the first bias signal, and outputting an addition / subtraction signal Means and a first control means for inputting the addition / subtraction signal and outputting a control signal for opening / closing the flow rate control valve to control the exhaust heat flow rate; and a level setting signal for the low pressure steam generator. The second bias signal is output based on the level setting means that outputs and calculates and outputs the level deviation signal between the level setting signal and the level detection signal of the first level detector, and the addition / subtraction signal of the first control means. Second bias setting means, addition / subtraction means for adding / subtracting the level deviation signal, the second bias signal, and the third bias signal to output an addition / subtraction signal, and the addition / subtraction signal The Enter the first
Outputting a level setting signal of the high-pressure evaporator, and second control means comprising control arithmetic means for opening and closing the level control valve to output a control signal for controlling the level of the low-pressure evaporator,
Level setting means for calculating and outputting a level deviation signal between the level setting signal and the level detection signal of the second level detector, a temperature detection signal of the first temperature detector and a temperature detection signal of the second temperature detector. Fifth bias signal based on the deviation signal between the temperature detection signal of the second temperature detector and the temperature detection signal of the third temperature detector. A fifth bias setting means for outputting, a high value priority means for outputting a signal having a higher value among the fourth bias signal and the fifth bias signal as a sixth bias signal, the level deviation signal and the second bias signal. Adder / subtractor means for adding / subtracting a bias signal and the sixth bias signal to output an add / subtract signal;
Third control means, which is a control calculation means for inputting the addition / subtraction signal and opening / closing the second level control valve to output a control signal for controlling the level of the high-pressure evaporator, and an inlet on the low-pressure side of the medium turbine. Pressure setting means for outputting a pressure signal and calculating and outputting a pressure deviation signal between the inlet pressure setting signal and the pressure detection signal of the fourth pressure detector, the pressure deviation signal, the first bias signal and the second Addition / subtraction output means for adding / subtracting a bias signal and the third bias signal to output an addition / subtraction signal and the addition / subtraction signal are input to open / close the second pressure control valve to control the inlet pressure on the low pressure side of the medium turbine. Fourth control means including control calculation means for outputting a control signal, and an inlet pressure signal on the high pressure side of the medium turbine are output, and the inlet pressure setting signal and the pressure of the third pressure detector are output. Pressure setting means for calculating and outputting a pressure deviation signal from the detection signal, and a seventh bias signal based on a deviation signal between the pressure detection signal of the second pressure detector and the pressure detection signal of the third pressure detector are output. A seventh bias setting means, an addition / subtraction means for adding / subtracting the pressure deviation signal, the second bias signal, the sixth bias signal and the seventh bias signal and outputting an addition / subtraction signal, and inputting the addition / subtraction signal Outputting a medium temperature setting signal for the condenser, and a fifth control means comprising a control calculation means for opening and closing the first pressure control valve to output a control signal for controlling the inlet pressure on the high pressure side of the medium turbine, A deviation signal between the medium temperature setting signal and the temperature setting signal for outputting the temperature detection signal of the fifth temperature detector, and the temperature detection signal of the fifth temperature detector and the temperature detection signal of the sixth temperature detector. An eighth bias setting means for outputting an eighth bias signal based on the above, an addition / subtraction means for adding / subtracting the temperature deviation signal, the second bias signal, and the eighth bias signal to output an addition / subtraction signal, and inputting the addition / subtraction signal Then, the sixth control means including a control calculation means for opening and closing the temperature control valve and outputting a control signal for controlling the medium temperature of the condenser is provided.

[0011]

In the first control means, the deviation signal between the first pressure detector of the low pressure evaporator of the medium system and the fourth pressure detector of the low pressure side inlet of the medium turbine is used as the first bias signal in advance as the exhaust heat deviation. Since it is added to the signal, the secondary delay in heat exchange in the low pressure evaporator is compensated. Therefore, the opening of the flow rate control valve at the outlet of the low pressure preheater is controlled to reach the set value by following the set power of the medium turbine generator.

In the second control means, the second bias signal based on the exhaust heat flow rate deviation signal of the first control means, the third temperature detector at the inlet of the low pressure evaporator of the exhaust heat system and the fourth at the outlet of the low pressure evaporator. Since the third bias signal based on the deviation signal from the temperature detector is added to the medium level deviation signal, the secondary delay when heat is exchanged in the low pressure evaporator is compensated, and the level set value of the low pressure evaporator is adjusted. Following this, the opening of the first level control valve is controlled so as to reach the set value.

In the third control means, a fourth bias signal based on the second bias signal and a deviation signal between the first temperature detector at the inlet of the high pressure evaporator and the second temperature detector at the outlet, and the high pressure preheater inlet. Since the high value obtained by comparing the fifth bias signal based on the deviation signal between the second and third temperature detectors at the outlet and the fifth bias signal based on the deviation signal is added in advance to the level deviation signal as the sixth bias signal, Compensating for the secondary delay when exchanging heat, following the level setting value of the high pressure evaporator,
The opening of the second level control valve on the inlet side of the high-pressure evaporator is controlled so as to reach the set value.

Since the fourth control means adds the first bias signal, the second bias signal and the third bias signal to the inlet pressure deviation signal of the medium turbine, the inlet pressure on the low pressure side of the medium turbine is compensated. The inlet pressure on the low pressure side of the medium turbine is controlled by the opening degree of the second pressure control valve so as to reach the set value.

In the fifth control means, the second bias signal, the sixth bias signal, the seventh bias signal based on the deviation between the pressure detection signal of the second pressure detector and the third pressure detection signal of the medium turbine are output. It is added to the inlet pressure deviation signal to compensate the low pressure side inlet pressure of the medium turbine, and is controlled so that the low pressure side inlet pressure of the medium turbine becomes a set value by the opening of the first pressure control valve of the medium turbine bypass. It

In the sixth control means, the eighth bias signal and the second bias signal based on the deviation signal between the temperature detection signal of the fifth temperature detector and the temperature detection signal of the sixth temperature detector are added to the temperature deviation signal. By performing the compensation, the opening of the temperature control valve at the inlet of the condenser is controlled so that the temperature in the hot well tank becomes the set value. Therefore, by following the power load setting of the medium turbine, the secondary delay at the time of heat exchange of the high pressure evaporator and the low pressure evaporator, the high pressure preheater and the low pressure preheater, and the condenser is compensated in advance, and the transient It is possible to stably control the exhaust heat flow rate and temperature fluctuation, the low boiling point medium flow rate and temperature fluctuation, the cooling water temperature and flow rate fluctuation.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall system diagram of an exhaust heat utilization power generation control device showing an embodiment of the present invention. This system comprises an exhaust heat system 1, a medium system 2, and a cooling water system 3.

In the figure, in an exhaust heat system 1, high-temperature hot water and exhaust heat from a production well are pumped up by an exhaust heat pump 4 and exchange heat with the medium in a high-pressure evaporator 5, and are supplied to a high-pressure preheater 6 as a medium. The heat is exchanged, the heat is exchanged with the medium supplied to the low-pressure evaporator 7, and the heat is exchanged with the medium supplied to the low-pressure preheater 8 to be reduced to the reduction well.

In the medium system 2, the medium is supplied to the low-pressure preheater 8 by the medium pump 9, where the medium is heat-exchanged and branched from the outlet side of the low-pressure preheater 8 to the first medium system 2
a and the second medium system 2b.

In the first medium system 2a, the medium is the medium pump 1
0, it is supplied to the high-pressure preheater 6, where it is exchanged with high-pressure and high-temperature exhaust heat and hot water, and further, the medium is supplied to the high-pressure evaporator 5 and is exchanged with high-temperature exhaust heat and hot water. , The medium gas is supplied to the medium turbine 11 under a predetermined pressure condition to drive the generator 12, and then the medium gas is
The second medium system 2b and the medium system 2 join together, flow into the condenser 13, exchange heat with the cooling water, become a medium, and are collected in the hot well tank 14.

The second medium system 2b has a low pressure preheater 8
The medium is supplied to the low-pressure evaporator 7 from the outlet side of
The medium gas is heat-exchanged and supplied to the medium turbine 11 under a predetermined pressure condition to drive the generator 12, and joins with the first medium system 2a to form the medium system 2.

Further, the first medium system 2a is provided with a bypass system 2c for biasing the medium turbine 11 with the medium gas under a predetermined pressure condition, and the second medium system 2b is treated with the medium gas under the predetermined pressure condition for the medium turbine 11. The bypass system 2e that joins with the bypass system 2d that biases the is connected to the outlet side of the medium turbine 11.

The cooling water system 3 supplies cooling water to the condenser 13. As the medium, for example, a substance having a low boiling point such as CFC is used.

The exhaust heat system 1 includes a flow rate detector 15, a first temperature detector 16, a second temperature detector 17, a third temperature detector 18, a fourth temperature detector 19, and a flow rate adjustment. Valve 20
And a first pressure detector 21 and a first level detector 22 in the low-pressure evaporator 7, and a level adjustment on the inlet side of the low-pressure evaporator 7 in the second medium system 2b. A valve 23 is arranged.

Further, in the first medium system 2a, a second pressure detector 24 and a second level detector 25 are arranged in the high pressure evaporator 5, and a level control valve 26 is provided at the outlet side of the low pressure preheater 8.
Is arranged, the third pressure detector 27 is arranged on the inlet side of the medium turbine 11 of the first medium system 2a, and the fourth pressure detector 2 is arranged on the inlet side of the medium turbine 11 of the second medium system 2b.
And 8 are arranged.

Further, a pressure regulating valve 29 is arranged in the bypass system 2c, and a pressure regulating valve 3 is arranged in the bypass system 2d.
0 is placed. A fifth temperature detector 31 is arranged on the outlet side of the condenser 13 of the medium system 2, and a sixth temperature detector 32 is arranged on the hot well tank 14. Further, the cooling water system 3 is provided with a temperature control valve 33 and a cooling water pump 34.

The detection signal of each detector described above is shown in FIG.
Further, it is input to the control device 40 shown in FIG. 3 for control calculation to control each control valve.

In this embodiment, as the first control means, the first pressure detector 21 of the low-pressure evaporator 7 is preceded by the deviation signal from the exhaust heat flow rate signal with respect to the power load setting of the generator 12. The deviation signal obtained by adding and subtracting the first bias signal a based on the pressure signal with the fourth pressure detector 28 on the inlet side of the medium turbine 11 is used as the PID as the exhaust heat flow rate deviation signal for controlling the opening and closing of the flow rate control valve 20. The input is made to the controller 41.

As the second control means, the second bias based on the exhaust heat flow rate deviation signal of the first control means is preceded by the deviation signal of the level setting of the low pressure evaporator 7 from the medium level of the low pressure evaporator 7. The deviation signal obtained by adding and subtracting the signal b and the third bias signal c based on the exhaust heat flow deviation signal at the inlet and outlet of the low pressure evaporator 7 is used as the level deviation signal for controlling the opening and closing of the level adjusting valve 23 as the PID controller 42. I am trying to type in.

As a third control means, when the level of the high-pressure evaporator 5 is set, the deviation signal from the medium level of the high-pressure evaporator 5 is preceded by the exhaust heat temperature deviation signal of the inlet and the outlet of the high-pressure evaporator 5. Of the fourth bias signal d based on this and the fifth bias signal e based on the temperature deviation signal at the inlet and outlet of the high-pressure preheater 6, whichever has the higher value is set as the sixth bias signal f,
A deviation signal obtained by adding and subtracting the bias signal f and the second bias signal b is input to the PID controller 43 as a level deviation signal for controlling the opening / closing of the level adjusting valve 26.

As a fourth control means, the deviation signal from the inlet pressure of the medium turbine 11 with respect to the inlet pressure setting of the medium turbine 11 is preceded by a first bias signal a, a second bias signal b, and a third bias signal. A deviation signal obtained by addition and subtraction of c and c is input to the PID controller 44 as a pressure deviation signal for controlling the opening and closing of the pressure adjusting valve 30.

As the fifth control means, the deviation signal from the inlet pressure of the medium turbine 11 with respect to the inlet pressure setting of the medium turbine 11, the pressure signal of the medium turbine 11 and the pressure signal of the high-pressure evaporator 5 are preceded. The deviation signal obtained by adding and subtracting the seventh bias signal g, the second bias signal b, and the sixth bias signal f based on the pressure deviation signal of No. 1 to the PID controller 45 as a pressure deviation signal for controlling the opening and closing of the pressure adjusting valve 29. I am trying to enter.

As the sixth control means, with respect to the medium temperature setting on the outlet side of the condenser 13, the deviation signal between the medium temperature signal and the medium temperature signal of the hot well tank 14 is preceded by the deviation signal from the medium temperature signal. Eighth bias signal h based on the signal
The deviation signal obtained by adding and subtracting the second bias signal b and P is used as P as the temperature deviation signal for controlling the opening and closing of the temperature control valve 33.
The input is made to the ID controller 46.

With the above structure, first, the exhaust heat flow rate of the exhaust heat system 1 is controlled by the first control means of the control device 40 shown in FIGS. 2 and 3 as follows.

In the control device 40, the detection signal of the flow rate detector 15 is converted into a linear signal by the square root calculator 47, and this signal is compared with the current load setting signal by the power setting device 48. The obtained deviation signal is added to the addition / subtraction arithmetic unit 49, and in the addition / subtraction arithmetic unit 49, the following first bias signal a
Is added / subtracted by the symbols shown and input to the PID controller 41.

That is, in the addition / subtraction calculator 50, the detection signal of the fourth pressure detector 28 and the detection signal of the first pressure detector 21 of the low-pressure evaporator 7 are added / subtracted, and the bias device is based on this addition / subtraction signal. It is input to the addition / subtraction calculator 49 as the first bias signal a by 51.

The control signal from the PID controller 41 is converted into an air signal by the electropneumatic converter 52 to control the opening of the flow rate control valve 20. As a result, the exhaust heat flow rate is controlled by following the power set value of the generator 12 of the medium turbine 11.

Next, in the second control means, the detection signal of the first level detector 22 of the low pressure evaporator 7 is the level setter 53.
And the deviation signal is compared with the level setting signal of
Added to. Further, the second bias signal b and the third bias signal c are added to the adder / subtractor 54.

That is, the second bias signal b is biased by the bias unit 55 based on the exhaust heat flow rate deviation signal from the addition / subtraction calculator 49. Further, in the adder / subtractor 56, the current signal obtained by converting the detection signal of the third temperature detector 18 at the inlet of the low pressure evaporator 7 by the temperature converter 57 and the fourth temperature detector 19 at the outlet of the low pressure evaporator 7 are detected. The detection signal and the current signal converted by the temperature converter 58 are added, and this addition / subtraction signal is made the third bias signal c by the bias device 59.

The output signal of the adder / subtractor 54 is input to the PID controller 42, and the control signal thereof is converted into an air signal by the electropneumatic converter 60 and the opening degree of the level adjusting valve 23 is increased / decreased. The level is controlled.

Next, in the third control means, the detection signal of the second level detection signal 25 of the high pressure evaporator 5 is the level setting device 6.
It is compared with the level setting signal of 1, and the obtained deviation signal is added to the adder / subtractor 62. Further, the adder / subtractor 62 is added with the second bias signal b and the sixth bias signal f.

That is, in the adder / subtractor 63, the current signal obtained by converting the detection signal of the first temperature detector 16 at the inlet of the low pressure evaporator 7 by the temperature converter 64 and the second temperature detection at the outlet of the low pressure evaporator 7. The detection signal of the device 17 is added to the current signal converted by the temperature converter 65, and the addition / subtraction signal is input to the high value priority device 67 described later as the fourth bias signal d by the bias device 66.

In addition, in the adder / subtractor 68, the current signals of the temperature converter 57 and the temperature converter 65 described above are added,
The addition / subtraction signal is input to the high price priority device 67 as the fifth bias signal e by the bias device 69.

In the high price priority device 67, the fourth bias signal d
And the fifth bias signal e, whichever is higher,
The bias signal f is used.

The output signal of the adder / subtractor 62 is input to the PID controller 43, the control signal of which is converted into an air signal by the electropneumatic converter 70, and the opening degree of the level adjusting valve 26 is increased or decreased to increase or decrease the pressure of the high pressure evaporator 5. The level is controlled.

Next, in the fourth control means, the medium turbine 1
The detection signal of the fourth pressure detector 28 at the inlet of 1 is compared with the pressure setting signal of the pressure setting device 71, and the obtained deviation signal is added to the adder / subtractor 72. The 1-bias signal a, the second bias signal b, and the third bias signal c are added / subtracted by the symbols shown.

The output signal of the adder / subtractor 72 is input to the PID controller 44, the control signal thereof is converted into an air signal by the electropneumatic converter 73, and the opening / closing of the pressure control valve 30 is increased / decreased to cause the medium turbine 11 to move. The inlet pressure is controlled.

Next, in the fifth control means, the medium turbine 1
The detection signal of the third pressure detector 27 at the inlet of 1 is compared with the pressure setting signal of the pressure setter 74, the obtained deviation signal is added to the adder / subtractor 75, and the adder / subtractor 75 also outputs the second bias signal. b, the sixth bias signal f, and the seventh bias signal g are added / subtracted by the symbols shown.

That is, in the adder / subtractor 76, the detection signal of the third pressure detector 27 and the detection signal of the second pressure detector 24 are added and subtracted, and the addition and subtraction signal is converted into the seventh bias signal g by the bias device 77. There is.

The output signal of the adder / subtractor 75 is input to the PID controller 45, the control signal thereof is converted into an air signal by the electropneumatic converter 78, and the inlet of the medium turbine 11 is changed by increasing or decreasing the opening degree of the pressure adjusting valve 29. The pressure is controlled.

Next, in the sixth control means, the detection signal of the fifth temperature detector 31 at the outlet of the condenser 13 is the temperature converter 79.
Is converted into a temperature detection signal by the input to the temperature setting device 80, which is compared with the temperature setting signal,
The obtained deviation signal is added to the adder / subtractor 81, and
In the adder / subtractor 81, the second bias signal b and the eighth bias signal h are added / subtracted by the symbols shown.

That is, in the adder / subtractor 82, the current signal from the temperature converter 79 and the current signal obtained by converting the detection signal of the sixth temperature detector 32 of the hot well tank 14 by the temperature converter 83 are added and subtracted. The addition / subtraction signal is made into the eighth bias signal h by the bias device 84.

The output signal of the adder / subtractor 81 is input to the PID controller 46, the control signal thereof is converted into an air signal by the electropneumatic converter 85, and the opening degree of the temperature control valve 33 is increased / decreased to cause the condenser 13 to cool. The outlet temperature is controlled.

Therefore, according to this embodiment, the medium turbine 1
Following the power load setting of No. 1, the secondary delay in heat exchange of the high-pressure evaporator and low-pressure evaporator, the high-pressure preheater and low-pressure preheater, and the condenser is compensated in advance, and the transient exhaust heat is removed. In addition, stable control can be achieved against fluctuations in low boiling point medium and cooling water temperature / flow rate.

[0056]

As described above, according to the present invention, the high-pressure evaporator according to the exhaust heat flow rate and the temperature fluctuation of the high-pressure evaporator and the low-pressure evaporator to the exhaust heat system with respect to the power setting load of the exhaust heat utilization power plant. And to prevent fluctuations in the medium evaporation pressure of the low-pressure evaporator, and also to prevent fluctuations due to secondary delay during exhaust heat and medium heat exchange in the high-pressure preheater and low-pressure preheater, and to prevent transient load fluctuations. Bias signals of the medium temperature change rate at the inlet and outlet of the high pressure evaporator and the low pressure evaporator of the exhaust heat system, the cooling water temperature of the condenser and the inlet medium temperature change rate of the high pressure evaporator and the low pressure evaporator By controlling the opening degree of the exhaust heat flow rate control valve, control can be achieved by following the set power of the generator of the medium turbine, and the fluctuation of the inlet pressure of the medium turbine can be reduced as much as possible. Heat system, medium System, to improve the heat exchange efficiency of the condenser cooling water system, can be stably controlled against transient load variations and can operate with high efficiency.

[Brief description of drawings]

FIG. 1 is a system diagram of an exhaust heat utilization power plant showing an embodiment of the present invention.

FIG. 2 is a block diagram of the first half of a control device that controls the power plant using exhaust heat in FIG.

FIG. 3 is a block configuration diagram of the latter half of a control device that controls the exhaust heat utilization power generation plant of FIG. 1.

[Explanation of symbols]

 1 Exhaust Heat System 2 Medium System 3 Cooling Water System 4 Exhaust Heat Pump 5 High Pressure Evaporator 6 High Pressure Preheater 7 Low Pressure Evaporator 8 Low Pressure Preheater 9,10 Medium Pump 11 Medium Turbine 12 Generator 13 Condenser 14 Hotwell Tank 15 Flow rate detector 16 First temperature detector 17 Second temperature detector 18 Third temperature detector 19 Fourth temperature detector 20 Flow rate adjusting valve 21 First pressure detector 22 First level detector 23 , 26 Level control valve 24 Second pressure detector 25 Second level detector 27 Third pressure detector 28 Fourth pressure detector 29, 30 Pressure control valve 31 Fifth temperature detector 32 Sixth Temperature detector 33 Temperature control valve 40 Control device

Claims (1)

[Claims] 1. High-temperature hot water and exhaust heat are taken in by an exhaust heat pump and sequentially supplied to a high-pressure evaporator, a high-pressure preheater, a low-pressure evaporator and a low-pressure preheater, and an exhaust heat system for exchanging heat with each and a hot The medium pumped from the well tank to the low-pressure preheater, the low-pressure evaporator, the high-pressure preheater, and the high-pressure evaporator in order by the medium pump, and the high-temperature hot water, the heat exchanged with the exhaust heat, and the temperature-increased medium The medium is evaporated to a specified pressure by the low-pressure evaporator and the high-pressure evaporator, the vaporized gas of the medium is supplied to the high-pressure side and the low-pressure side of the medium turbine, the generator of the medium turbine is driven, and the exhaust gas of the medium turbine is It consists of a medium system that flows into a condenser and is cooled with cooling water to be collected in the hot well tank and circulated, and a cooling water system that cools exhaust gas of a medium turbine with cooling water in the condenser. In an exhaust heat utilization power generation control device for controlling an exhaust heat utilization power generation plant, the exhaust heat system includes a flow rate detector, a first temperature detector, and a second temperature detector.
A temperature detector, a third temperature detector, a fourth temperature detector and a flow rate control valve are arranged respectively, and a low pressure side of the medium system includes a first pressure detector and a first level detector in the low pressure evaporator. And a first level control valve on the inlet side of the low pressure evaporator, and a second pressure detector and a second level detector on the high pressure evaporator on the high pressure side of the medium system. A second level control valve is arranged on the inlet side of the high pressure preheater, a third pressure detector is arranged on the inlet side of the medium turbine on the high pressure side of the medium system, A fourth pressure detector is disposed on the inlet side, a first pressure control valve is disposed on the high pressure bypass system, and a second pressure control valve is disposed on the low pressure side bypass system to condense the medium system. A fifth temperature detector is placed on the outlet side of the vessel and the hot well tank is 6 temperature detectors are arranged, a temperature control valve and a cooling water pump are arranged in the cooling water system, the power setting signal of the medium turbine is output, and this power setting signal and the exhaust heat of the flow rate detector are output. A power setting means for calculating and outputting an exhaust heat flow rate deviation signal from the flow rate signal;
First bias signal setting means for outputting a first bias signal based on a deviation signal between the pressure signal of the pressure detector and the pressure signal of the fourth pressure detector, the exhaust heat flow rate deviation signal and the first bias First control means including addition and subtraction means for adding and subtracting a signal and outputting an addition and subtraction signal, and control calculation means for inputting the addition and subtraction signal and opening and closing the flow rate control valve to output a control signal for controlling the exhaust heat flow rate And level setting means for outputting a level setting signal of the low-pressure steam generator and calculating and outputting a level deviation signal between the level setting signal and the level detection signal of the first level detector,
Second bias setting means for outputting a second bias signal based on the addition / subtraction signal of the first control means; and the third bias setting means.
Third bias signal setting means for outputting a third bias signal based on a temperature deviation signal between the temperature detection signal of the temperature detector and the temperature detection signal of the fourth temperature detector, the level deviation signal and the second bias signal. Signal and the third bias signal are added and subtracted to output an addition and subtraction signal, and an addition and subtraction signal is input to output a control signal for opening and closing the first level control valve to control the level of the low-pressure evaporator. Level setting signal for outputting a level setting signal for the high-pressure evaporator and for calculating and outputting a level deviation signal between the level setting signal and the level detection signal for the second level detector. Means and said first
Fourth bias setting means for outputting a fourth bias signal based on a deviation signal between the temperature detection signal of the temperature detector and the temperature detection signal of the second temperature detector; the temperature detection signal of the second temperature detector; Fifth bias setting means for outputting a fifth bias signal based on a deviation signal from the temperature detection signal of the third temperature detector, and a signal having a higher value out of the fourth bias signal and the fifth bias signal High-value priority means for outputting as a 6-bias signal, addition-and-subtraction means for adding and subtracting the level deviation signal, the second bias signal, and the sixth bias signal, and outputting an addition-and-subtraction signal, A third control means including a control calculation means for opening and closing a two-level control valve to output a control signal for controlling the level of the high-pressure evaporator; and an inlet pressure setting on the low pressure side of the medium turbine. A pressure setting means for outputting a constant signal and calculating and outputting a pressure deviation signal between the inlet pressure setting signal and the pressure detection signal of the fourth pressure detector; the pressure deviation signal, the first bias signal and the second Addition / subtraction output means for adding / subtracting a bias signal and the third bias signal to output an addition / subtraction signal, and inputting the addition / subtraction signal to open / close the second pressure control valve to control the inlet pressure on the low pressure side of the medium turbine And a fourth control means for outputting a control signal for outputting a control signal for controlling the inlet pressure setting signal for the high pressure side of the medium turbine, and the inlet pressure setting signal and the pressure detection signal for the third pressure detector. And a seventh bias signal based on a deviation signal between the pressure detection signal of the second pressure detector and the pressure detection signal of the third pressure detector. A seventh bias setting means, an addition / subtraction means for adding / subtracting the pressure deviation signal, the second bias signal, the sixth bias signal, and the seventh bias signal to output an addition / subtraction signal, and inputting the addition / subtraction signal. Fifth control means comprising a control calculation means for opening and closing the first pressure control valve to output a control signal for controlling the inlet pressure on the high pressure side of the medium turbine; and outputting a medium temperature setting signal for the condenser, Temperature setting means for calculating and outputting a temperature deviation signal between the medium temperature setting signal and the temperature detection signal of the fifth temperature detector, a temperature detection signal of the fifth temperature detector and a temperature detection of the sixth temperature detector. Eighth bias setting means for outputting an eighth bias signal based on a deviation signal from the signal, the temperature deviation signal, and the second
Addition / subtraction means for adding / subtracting a bias signal and the eighth bias signal to output an addition / subtraction signal; and a control signal for inputting the addition / subtraction signal to open / close the temperature control valve and control the medium temperature of the condenser. An exhaust heat utilization power generation control device comprising a sixth control means comprising a control calculation means.